Spool valve o-ring sealed spool



Aug. 22, 1961 c. JOHNSON SPOOL VALVE 0-RING SEALED SPOOL Original FiledMay 11, 1955 6 Sheets-Sheet 1 INVENTOR 3 RNE &

lIIlHHIIII Aug. 22, 1961 c. JOHNSON SPOOL VALVE 0 Original Filed May 11,1955 RING SEALED SPOOL 6 Sheets-Sheet 2 IN VENTOR ATTORNEYS Aug. 22,1961 c. JOHNSON 2,997,065

SPOOL VALVE O-RING SEALED SPOOL Original Filed May 11, 1955 6Sheets-Sheet 3 lOl r 7 J] INVENTOR C LA RE/VCE JOHNSON BY M yxw WATTORNEY5 Aug. 22, 1961 c. JOHNSON 2,997,065

SPOOL VALVE O-RING SEALED SPOOL Original Filed May 11, 1955 6Sheets-Sheet 4 ww w ATTORNEYS Aug. 22, 1961 c. JOHNSON SPOOL VALVEO-RING SEALED SPOOL Original Filed May 11, 1955 6 Sheets-Sheet 5 Q 5 Wmi Mb I n H 5 7; mm m NA E EN .Rw M3 m2 3 v n? l| 3 H| Q3 m: RK 0: 3L

INVENTOR CLARENCE Jam/sou BY w yw ATTORNEY5 Aug. 22, 1961 c. JOHNSON2,997,065

SPOOL VALVE O-RING SEALED SPOOL Original Filed May 11, 1955 6Sheets-Sheet 6 a7 ca INVENTOR CLARENCE JoH/vso/v 7 2o 66 BY l/w wATTORNEYS ga es Fatented Aug. 22, 1961 2,997,065 SPOOL VALVE O-RINGSEALED SPOOL Clarence Johnson, 1804' Green Road, South Euclid 21, OhioOriginal application May 11, 1955, Ser. No. 507,533. Divided and thisapplication Mar. 25, 1958, Ser. No. 731,563

10 Claims. (Cl. 137-622) The present invention relates to control valvesand more particularly to lever operated spool valves for controlling thesupply of fluid to the servo-motors used in servomotor poweredproduction equipment. This application is a division of applicantscopending application Serial No. 507,533, filed May 11, 1955 as acontinuation-in-part of copending application Serial No. 348,942 ofClarence Johnson entitled Valves filed April 15, 1953, now Patent No.2,912,007.

While control valves designed for servo-motor control usage haveheretofore been proposed, the prior control valves have been more orless special design or tailor made valves designed for a particularusage. As a consequence, the prior proposed valves have been relativelyexpensive and not suited for quantity production.

A primary object of this invention, therefore, resides in the productionof spool control valves of various sizes having different passagearrangements from a minimum number of basic quantity production elementsto provide valves suitable for specifically different control systemsand a novel method of making such valves to minimize the inventory ofparts to be stocked by the manufacturer.

Another object of the present invention is to provide a control valve ofthe character heretofore mentioned with a spool assembly that may beutilized to control the flow of either gaseous fluids or liquidstherethrough.

Another object of this invention is to provide a control valve of thecharacter heretofore mentioned with a simple and inexpensive spoolassembly adapted for selective use on any one of several different typesof valves.

Still another object of the present invention is to provide the spoolelement of a spool type control valve with sealing O-rings of resilientmaterial having special characteristics to assure seals of maximumsealing efliciency at all points and a suificiently high modulus ofelasticity at points passing over the outlet ports where the ring actedon by the high pressure control fluid is subjected to an extremely lowerpressure at the outlet ports conducive to permitting a blow out of thering into the outlet port.

Still further objects of the present invention will appear from thefollowing description and appended claims when read in conjunction withthe accompanying drawings wherein:

FIGURE 1 is an elevational view of one embodiment of a four Way valveembodying certain of the improvements of this invention shown installedin a diagrammatically illustrated servo-motor system and adapted forhand operation;

FIGURE 2 is a transverse sectional view through the valve of FIGURE 1taken substantially on line 22 of FIGURE 1 when viewed in the directionof the arrows;

FIGURE 3 is an elevational view of a preferred form of four way valvesimilar to but longitudinally shorter than the valve of FIGURE 1illustrating a specifically different and preferred form of handactuated operating assembly;

FIGURE 4 is an end view of the valve of FIGURE 3 viewed from the rightend, certain portions of the hand actuated operating assembly beingshown in section;

FIGURE 5 is a longitudinal sectional view taken on line -5--5 of FIGURE3 showing the details of the four way valve of FIGURE 3;

FIGURE 6 is a view similar to FIGURE 4 illustrating a modified form ofhand actuated operating assembly applied to a four way valve of largerfluid capacity than that shown in FIGURES 3 and 4;

FIGURE 7 is a side View on a smaller scale of the four way valve ofFIGURE 3 equipped with a foot treadle operator in place of the handlever of FIGURE 3;

FIGURE 8 is a fragmental side view of a four Way valve like that ofFIGURE 6 equipped with a cam operator in place of the hand lever ofFIGURE 6;

FIGURE 9 is an end view of the valve and operator of FIGURE 8 viewedfrom the right hand end of FIG- URE 8;

FIGURE 10 is a fragmental side view similar to FIG- URE 8 illustratingthe valve of FIGURE 8 equipped with a foot pedal operator;

FIGURE 11 is a side view of a three way valve made in accordance withthis invention viewedfrom the inlet side or side opposite that of theprevious figures showing a hand operator like that of FIGURE 3 mountedon the opposite end of the valve;

FIGURE 12 is a longitudinal sectional view taken on line 12ll2 of FIGURE11 looking in the direction of the arrows and illustrating the detailsof the three way valve of FIGURE 11;

FIGURE 13 is a view similar to FIGURE 12 illustrating the details of atwo way valve 'made in accordance with the present invention;

FIGURE 13A is an elevational view of a preferred spool construction withcertain parts in section for clarity of illustration; and

FIGURE 14 is a detailed sectional view through one of the intermediatelever elements provided by this invention.

With continued reference to the drawings wherein like reference numeralsare used throughout to indicate the same parts and with particularreference for the moment to FIGURES l and 2, a four way valve 20 made inaccordance with the present invention is illustrated connected throughpipe lines 21 and 22 to a servo-motor 23. While control of servo-motor23 as illustrated is one use for the valves of this invention, it willbe appreciated that the valves may be connected to other servo-motormechanisms or similar devices in various Ways to accomplish desiredcontrol functions. As illustrated, servo-motor 23 comprises a cylinder24 and a double acting piston 25 disposed therein for reciprocatingmovement. The piston rod 26 is connected in any conventional manner to amachine tool table, tool, cross slide or the like or any other deviceadapted to be moved at a controlled rate as Will be clear to thoseskilled in the art.

While valve 20 may be actuated automatically or manually, the presentinvention contemplates a readily separable lever type operator of anyone of several different types and a unique body and spool structureadapting such control valves for quantity production in spite of thecustomary special operating functions. To this end, valve 2t) comprisesa valve body or housing 27 of generally elongated form having alongitudinally extending bore or passage 28 adapted to receive separableliner sleeves for slidingly supporting a valve member in the form of areciprocating spindle 29. While body or housing 27 may be supported inany suitable way, each of the illustrated embodiments embodies supportfeet 31 adapting; the body for bolted attachment to a mounting plate orthe like (not shown) in a manner well known to the art.

To effect manufacturing and inventory economies, the present inventionproposes to eliminate as far as possible the need for different valvehousings in the standard A",

/s" and /2 three and four way valves and the need for careful machinefitting of the valve parts in all types and sizes of valves. To thisend, the same housing 27 is employed in the four way valves of the A3"and 4 sizes, (FIGURES l-S and 7), a similar housing 27A having a widerbody (FIGURES 6, 8, 9, 10) is used in the four way valves of /2 size, adifferent housing 273 (FIGURES l1 and 12) is used for the three way /2"valves, a similar but narrower body (not shown) is used for the threeway valves of the and 4 sizes, and a similar but shorter housing 27C(FIGURE 13) is used for the two way valves. The basic housings in allcases are produced in block form. All of the bodies are of generallyelongated form and are preferably provided with end flanges or faces 32of identical shape and size (FIGURES 3 through 13). The four way valvebodies in the A, and /2" sizes are provided with a laterally offset,longitudinally directed, body formation 34 along one side to provide forthe desired exhaust porting.

In all of the four way valves, the valve bore 28 and inlet port 35longitudinally centered along the side opposite formation 34 are drilledand tapped to the desired size at the time an order for a particularsize valve is received. Each of these bodies, has a cored exhaust port36 tapped to size and arranged diametrically opposite the inlet port anda cored manifold passage 37 extending longitudinal of body formation 34and terminating short of the body ends and intersecting the exhaust port36 formed in the body formation 34. Bore 28 connects with the oppositeends of manifold passage 37 through drilled passages (FIGURES 2 andformed as hereinafter pointed out. In the /2" four way valves, formation34, due to the necessarily larger diameters of bore 28 and passage 37required to handle the greater fluid flow, is substantially larger thanin the /4" and bodies (see FIGURES 6 and 8 through 11).

In the three way valves, the formation 34 and manifold passage 37 areomitted and a pair of longitudinally spaced drilled and tapped outletports 38, symmetrically disposed at either side of the longitudinalcenter of the body, are provided (see FIGURE 12) at the same time thatbore 28 is drilled. In the two way valves (FIGURE 13), the inlet port 35and an outlet port 38, offset and located on opposite sides of the valvebody, are drilled and tapped to the desired size at the same time thatthe bore 28 is drilled.

All of the four way valves are provided with longitudinally spaced pairsof drilled outlet ports 39 and 41 (FIGURE 1) formed in longitudinallyspaced bosses 42 and 43 (FIGURES l, 2, 3 and 7). Bore 28 and the variousports 35, 36, 38, 39 and 41 are all suitably drilled and tapped to sizeon order so that a manufacturer can make up his anticipated requirementsof basic valve bodies of each style, namely, two way, A" and four way,A", /s" three way, A2 three Way and /2" four way.

Drilled bore 28 extending from end to end of the body provides a surfacefinish satisfactory for receipt of suitably formed intermediate linerelements 45 (FIGURE 14) and desired mating end liner elements 46 and 47(FIGURE 5). These liners are axially arranged in the desired order inbore 28 to form a longitudinally discontinuous guide bore 48 for thedesired valve spindle 29. To eliminate the need for a careful machinedfit between bore 28 and the liners, the present invention contemplatesthat the liners be formed with one or more annularly enlarged ribs 51each containing a ring groove and being of a diameter sufficiently lessthan that of bore 28 to assure a free sliding cooperation with bore 28or even a slight clearance as illustrated in FIGURES 5, l2 and 13. Asclearly seen in FIGURE 14, liners 45 are each provided with a pair ofsuch grooved ribs 51 respectively disposed symmetrically on either sideof a transverse plane passing through the longitudinal center of theliners. These paired ribs together with the annular wall 52 of reduceddiameter therebetween define an annular recess 53 the purpose of whichwill be hereinafter pointed out.

The opposite ends of each liner 45 are identically formed to provide endextensions 54 of the same axial dimensions and identical configuration.These extensions 54 are adapted, when a pair of liners 45 are assembledin bore 23 with suitable spacer screens 55 therebetween, to defineannular recesses 56 similar in length and depth to recesses 53 providedbetween pairs of ribs 51. Similar end extensions 54- are formed on theinner ends of end liners 46 and 47 to cooperate with the end extensionof an adjacent liner 45 to form respective annular recesses 57 and 58when similar screens 55 are disposed between the liners 45 and 46 and 45and 47 as more clearly disclosed in FIGURES 5, 12, and 13. Theextensions 54, as more clearly shown in FIGURE 14, are formed with aradii 60 at the intersection of the end faces and the guide bore 48.Each liner 45 in longitudinally centered relation with respect to recess53 is provided with a series of radial bores 59 the inner ends of which,at their intersection with bore 48 are also formed on a radii 60. Thepurpose of these radii will be hereinafter pointed out.

As clearly seen from FIGURES 5 and 12, end liners 46 are formed with asingle annular grooved rib 51 and a transversely disposed end face 61.When properly positioned in bore 48 with the required liners 45 and 47,end face 61 will be in the plane of the end face 62 of body member 27.By reference to FIGURES 5, l2 and 13, it will be seen that liners 47 arealso provided with a single ungrooved, annular rib 63 at the inner endof extension 54 and that the axial length thereof terminates short ofbody face to provide terminal extension 64 of reduced diameter adaptedto protrude through and beyond the end face 65 of housings 27 to 27C asin FIGURES l, 5, l2 and 13. These protrusions receive and center themounting plate 66 of an operating lever support bracket 67 and formtherewith an annular ring groove the purpose of which will presentlyappear. Bracket 67 may take the form of that illustrated in FIGURE 1 butpreferably is formed as illustrated in FIGURES 3 and 4 or FIGURES 6, 7,8, 9, l0 and 11 in which the base plate, midway between a pair ofopposed side edges and at a third side edge, is provided with an axiallyand radially extending overhanging support arm 68 of substantial lateralthickness.

To secure maximum utility out of the preferred form of bracket 67, theopposite end faces 62 and 65 of body member 27 are provided withequiangularly spaced, drilled and tapped screw openings 69, FIGURE 3,adapted to cooperate with similarly spaced tapped openings in base plate66. As a consequence, bracket arm 68 may be located at either end(compare FIGURES 11 and 12 to the remaining figures) and in any one of aplurality of angular positions with respect to the body 27 so as todispose the selected operating lever in the most desirable position foroperation. The end of each body member opposite that provided withbracket 67 is closed by a closure plate 71 secured thereto by suitablescrews 72.

While cover plate 71 may directly engage the end 62 of body 27, it ispreferred in the three and four way valve of FIGURES 3 through 12 that asealing gasket 73 be interposed between the cover plate and the end ofthe body. It will be appreciated that the tapped openings 69 in end 62of body member 27 are angularly disposed in exactly the same relation asthe openings 69 of end face 65 so that the operating lever bracketmember 67 may be selectively applied to either end of the body.

Referring for the moment to FIGURES 3 to ll on the one hand and FIGURESl2 and 13 on the other, it is to be noted that the shape and size of thebody end faces in all forms of bodies are of uniform shape anddimension. This is true irrespective of the rated size of the valve sothat brackets 67 and cover plates 72 will be interchangeable in allforms and sizes of valves. As a result at this interchangeability, itwill be appreciated that a manufacturer, dealer or distributor of thevalveswill not be required to stock varying sizes of cover members andbracket members for the various sizes and port arrangements of thestandard lines of valves.

Further manufacturing economies are effected through.

this invention, since the four way valve bodies 27 for the /s" and M1"rated valve sizes can be identical to start with irrespective of thesize of valve desired since the only. differences will be in thedrilling of the ports now to be described. Referring first to the valvesshown in FIG- URES 1 through 5 and FIGURE 7 there is disclosed a fourway valve of inch size. As clearly appears from FIGURES 1, 3, 5 and 7such a four way valve on opposite sides of the longitudinally centeredexhaust opening 36 are provided with tapped bores 81 and 82 closed bymetering plugs 83 having tapered valve tips 84 cooperating respectivelywith manifold passages 85, drilled and counterbored in suitable fashionby a tool extending through openings 81 and 82 to form valve seatscooperating with their respective metering plugs 83. Each of the plugs83 is suitably locked in adjusted position by means of lock nuts 86 in amanner well known to the art. By suitable adjustment of these meteringplugs 83 the flow of fluid through manifold passages 85 can be regulatedto secure any desired rate of flow into manifold passage 37 and outthrough the exhaust port 36. It will be appreciated, therefore, that thefour way valves of this invention are designed to control fluid flow toregulate the rate of back and forth movement of the piston 25 of theservomotor 23 or other device desired to be controlled.

It will further be appreciated that passages 81 and 82 can be merelyplugged in which event the four way valve can be used to merely vent theopposite sides of the servomotor piston 25 to the exhaust port 36without any flow restriction.

In order to provide the desired flow paths through the valves each ofring grooves 51 of the various liner elements 45, 46 and 47 is providedwith O-rings 87 formed of any suitable resilient material of suitablehardness adapted to support the liners 45, 46 and 47 in bore 28 and sealthe annular receses 53 respectively from the recesses 56 and 57 and 58.These O-rings should preferably be of a 'duronreter hardness of from 60to about 80 to assure maintenance of a free floating relationship of theliner elements 45, 46 and 47 in bore 28 while providing adequate sealingproperties. As a result of this O-ring structure, the various annularrecesses 53, 56, 57 and 58 are respectively adapted to form annularpassages connecting the interior bore 48 of the liner elements with oneor the other of po nts 35, 39, 41 or 85. Liner bore 48 receives thevalve spool 29 and cooperates therewith to provide multiple passagewaysfor conveying fluid from inlet 35 to one or the other of outlets 39, 41while alternately venting ports 41 and 39 to the exhaust port 36 throughmanifold 37. In order to seal the end of liner element 47 against fluidescaping through the mounting plate 66, the groove formed betweenannular rib 63 and the inner face of mounting plate 66 is provided withan O-ring 86 of 60 to about 80 durorneter hardness which seals bore 28and liner element 47 and is held in place by mounting plate 66.

Proper passage of fluid in bore 48 is assured by providing valve spool29 with axially spaced valving lands 91, 92 and 93 flanked on eitherside by ring grooves adapted to respectively receive O-rings forslidingly sup porting spindle 29 in bore 48 formed by the liner elements45, 46 and 47. The grooves at the inner end of land 91 and the inner endof land 93 are preferably provided with O-rings 94 of 90 Durometerhardness designed as hereinafter pointed out to resist the tendency ofthese rings to blow out through the exhaust ports in high presurseusage. The grooves at the outer ends of lands 91 and 93 are providedwith O-rings 96 of 80 Durometer hardness having a squeeze fit with bore48 and a diameter to substantially fill their respective grooves so asto form a firm support for spindle 29. The 0-rings 94 and O-rings 95 ofDurometer hardness in the other grooves are free floating in theirrespective grooves and have an outer diameter only slightly greater(preferably by 5% to 8%) than the diameter of the guide bore 48. Thewidth and depth of the receiving grooves for rings 94 and isapproximately 10% greater than the crosssectional diameter of theO-rings to assure a good sealing contact. As a result, actual sealingbetween the bore 48 of the liners and the spool 29 between the exhaustports and the high pressure passages is effected by the O-rings 94 whileO-rings 96 support the spool in its sliding movement and are primarilyrelied upon to seal the spindle ends against escape of leakage fluid orlow pressure exhaust fluid only. In practice it has been found that asqueeze of .005 inch is satisfactory for most applications of O-rings 96but a somewhat tighter or looser fit may be used.

Referring again to rings 94 and particularly to the left end of thespool in FIGURE 5, it will be appreciated that the ring 94 of land 91will pass across the annular recess 57 as the spool moves to its extremeleft hand position. As this ring 94 reaches the right hand edge ofrecess 57, it will be subjected to high pressure over its right handface and to atmospheric pressure over its left hand face. The resultinghigh pressure acting between the bottom of the ring groove and the innerperipheral face of the ring 94 effectively tends to force the O-ringradially and axially outward around the end of liner member 45. If thedifferential pressure is high and special precautions are not taken thering will distend and extrude through the opening into recess 57 as therestraining influence of the guide bore is progressively relieved due topassage of the spool across the recess opening. Under such conditionsand if such distention is of appreciable magnitude, the O-ring is liableto be blown out of the groove entirely or be sheared off by the landwhen it crosses the radius at the opposite side of recess 57. in orderto prevent such an occurrence without resort to relocation of theO-rings in the guide bore effecting a seal on the spool solely due tothe inherent contracting force of the O-ring itself or O-rings having anexcessive hardness, which would, therefore, wear faster, a specialO-ring configuration has been devised in which the ratio of the outerdiameter to the cross-sectional diameter is approximately 4 to 1. Withsuch proportions and the usual manufacturing tolerances, it is possibleto use 0- rings of material having a Durometer hardness factor as low as65, taking advantage of the better wearing qualities thereof without therisk of blowing out or severing the O-rings and at the same timeproviding a more effective seal, particularly when operating fluids ofhigher pressures are to be used.

Referring for the moment particularly to the spool position of FIGURES 1and 5, high pressure fluid entering the inlet port 35 will pass intoannular recess 56, through the screen in the bottom of recess 56 andinto the interior of bore 48 to the left of the pair of rings 95adjacent land 92, then along bore 48 in the space surrounding thereduced diameter stem of the spindle 29, then outwardly through theliner passages 59 into the left hand annular passage 53 to the right ofland 91 and through outlet port 39 leading to the left hand end of theservo-motor cylinder 34 as seen in FIGURE 1. It will, therefore, beappreciated that the high pressure fluid is confined to the passageslying between the lands 91 and 92 and acts to force the respectiveO-rings 94 and 95 toward their respective lands 91 and 92. The pressurefluid, therefore, finds its way into the ring grooves on the highpressure side and bottom of the O-rings 94 and 95 so as to force theO-rings laterally against the opposite side of their grooves andradially outwardly against the guide bore 48. Thus an effective seal isachieved between the annular contact surfaces of the guide bore and thelow pressure side of the groove in each case with the result that a moreeffective seal will be provided as the fluid pressure increases. At thissame time the recess 53 communicating with port 41 is vented to theexhaust port 36 through the portion of bore 48 surrounding the reduceddiameter portion of the spindle located between lands 92 and 93 andtheir adjacent O-rings 95 and 94 and through the metering orifice formedby right hand passage 85 and its conical metering valve 84 leading tothe manifold passage 37 and thence to the exhaust port 36.

Assuming now that spool 29 is to be moved to its next operating positionthe desired movement would be effected by moving the spool to the leftas seen in FIG- URES l and 5. The next position would be that in whichthe respective lands 91, 92 and 93 overlie the open bottom walls ofannular passages 56, 57 and 58 respectively to cut-off all flow throughthe valve. In this new position, the O-ring 94 adjacent land 91 will bedisposed in sealing engagement with bore 48 within the outer endextension 54 of the left hand liner member 45, the respective O-rings 95on the opposite sides of land 92 will be disposed to contact theadjacent inner end extensions 54 of the two liner elements 45 and theO-ring 94 adjacent land 93 will sealingly engage the bore 48 within theouter end extension 54 of the right hand liner element 45. It will beappreciated, therefore, that in this position of the spool 29 thesealing rings 95 will be disposed to cut off flow from the high pressureinlet passage 56 to either of the adjacent annular passages 53 andpressure resistive rings 94 will be positioned to trap high pressurefluid in the passages leading to the opposite sides of piston 25 andprevent its escape to the low pressure exhaust porting. Thus flow of thetrapped high pressure fluid is effectively prevented from the passages53 to their respective exhaust passages 57 and 58. As a consequence ahighly effective valve shut-off position is provided by the valve ofthis invention.

The next operating position of the spool would be that placing the inletpassage 35 in communication with the right hand passage 53 leading tothe opposite side of the servo-motor piston 25 through the port 41 andpipe 22. This position is reached by moving the spool 29 further to theleft as viewed in FIGURES l and to a position Where the land 91 and itsassociated O-n'ng 94 lie wholly within the portion of bore 48 formed bythe inner end of liner element 46, the land 92 and its associatedO-rings 95 lie wholly within the left hand liner element 45 and the land93 and its associated O-ring 94 lie Within the right hand end of theright hand liner element 45. In this position of the spool, fluidentering port 35 will pass from inlet passage 35 to the right of theright hand O-ring 95 adjacent land 92, axially along the portion of theport bore 48 surrounding the reduced spool section lying between lands92 and 93, into the right hand passage 53 and thence through port 41 andpipe 22 to the right hand side of servo-motor piston 25. Again an O-ring94 is located to seal off the incoming high pressure fluid from theexhaust porting. At this same time fluid from the left hand side of thepiston 25 will be exhausted through pipe 21, passage 39, annular recess53, formed by the left hand liner 45, ports 59, the portion of bore 48surrounding the reduced spool portion lying between the lands 91 and 92thence through annular passage 57 and its associated exhaust passage 85restricted by the conical metering plug formation 84, the manifoldpassage 37 and exhaust port 36. The radii 60 of extensions 54 and bores59 provide for smooth passage of O-rings 94, 95 and 96 past bores 59 andthe annular passages formed between the liner ends.

To avoid the possibility of an air trap at the left hand end of thespool 29 as the land 91 and its associated O-rings enter liner element46, the present invention contemplates that the sealing gasket 73 beprovided with a radial slot 101 (FIGURE 5) leading outwardly to a pointopposite the left hand end of manifold passage 37, as

viewed in FIGURE 5, to a drilled vent passage 102 communicating withmanifold passage 37. This structure, it will be appreciated, will assureany trapped fluid to the left of spool 29 being vented directly to themanifold passage 37 and exhaust port 36 so that no effective fluidlocking of the spool can take place during movement of the spool. Inreversal of the spindle movement this passage 102 and slot 101 willpermit reverse flow of fluid from the manifold passage to the left handend of the spool to prevent a vacuum lock upon reversal of the spoolmovement. Effective movement of the spool 29 between these variouspositions is accomplished through one or another of the lever operatorscarried by bracket 67 and now to be described.

Referring first to FIGURE 1, the arm 68 of bracket 67 is drilledradially inwardly from the top of arm 68 toward the spool bore to form adrilled opening 105 intersecting the spool bore. Opening 105 isrestricted at its innermost end to captively receive a ball detent 106 aportion of which protrudes into the spool bore to cooperate with one oranother of the ball detent grooves 107, 108 and 109 formed in thereduced end portion of the spool 29. Ball 106 is resiliently biased toits protruding position by a coil spring 111 held in place in bore 105by a suitable abutment screw 112 inserted into the outer tapped end ofdrilled opening 105. The arm 68 of bracket 67 outwardly from drilledpassage 105 is axially slotted at 113 to receive a shifter lever 114.Lever 114 is journalled on a pivot 115 carried by the bifurcated arms116 formed at the opposite sides of the slots 113. One arm of the lever114 depends from pivot 115 and terminates in a bifurcated end 117received in an axial slot 118 formed in the outer end of the reduced endportion of spool 29. Bifurcated end 117 engages a cross pin 119 carriedby the spool 29. In the position shown in FIGURE 1, the valve spool isin its extreme right hand position and ball 106 is engaged with annulargroove 107 to retain the spool in this position. Assuming spool 29 is tobe moved to the shut-off position, the rod 121 carried by the other arm122 of lever 114 is moved in a clockwise direction around pivot 115thereby forcing the spool 29 to the left and camming detent ball 106back into drilled passage 105 until groove 108 is opposite the ball.When the groove 108 reaches a position opposite ball 106 spring 111 willproject the ball into the groove and positively indicate to the operatorthat the next valve position has been reached. If desired the operatormay leave the valve in this position or may merely pass the spoolthrough this position to its next position in which groove 109cooperates with ball 106. It will be appreciated, therefore, that theoperator of FIGURE 1 provides a detent indication for the three valvepositions and provides a simple and effective operating mechanism forthe valve of FIGURE 1.

The bracket 67 of the present invention is preferably formed to supporta lever operating mechanism adapted to automatically maintain the spoolvalve member 29 in a selected one of its several positions. One form ofsuch automatic operator is illustrated in FIGURES 3 and 4 wherein thebracket arm 68 is axially slotted in parallel relation to the axis ofspool 29 as indicated at 125 and provided with oppositely facingcylindrical bosses 126 and 127 having upstanding ears 128 and 129disposed at opposite sides of slot 125. Bosses 126 and 127 mount anoperating lever 131 and associated biasing mechanism. As clearly seen inFIGURE 4, lever 131 is carried on a pivot pin 132 which is in turnsupported in an enlarged cross bore 133 intersecting slot 125 by meansof a shouldered disc 134 disposed in one of the outer ends of bore 133with its hexagon shaped head 135 abutting the outer face of boss 126 andthe shouldered hexagon head 136 of pin 132 abutting the outer face ofboss 127. Axial movement of disc 134 along pin 132 is prevented by asnap ring 137 cooperating with a groove in pin 132 and the outer face ofdisc 134 in well known manner.

Pin 132 at opposite sides of lever 131 pivotally supports respectivelevers 138 and 139 the upper ends of which are formed with integralupwardly extending fingers 140 and 141 disposed respectively adjacentthe edges 142 and 143 of lever 131. A pin 144 carried by lever 141respectively engages fingers 146 and 141 depending upon the direction ofmovement of lever 131 around pin 132 as will be presently pointed out.Respective stop pins 145 and 146 are mounted in the ears .128 and 129 ofbracket arm 68 with their axes lying in the vertical plane containingthe axis of pin 132 and their inner ends projecting into the slot 125and terminating short of the side faces of the lever 131. These stoppins abut the respective fingers 139 and 141 to limit movement of thelevers 138 and 139 in one direction. Each of the levers 138 and 139opposite the inner ends of the bores 133 are provided with drilledpassages 147 adapted to receive the terminal inner ends of respectivecoil springs 148 housed in the aligned portions of bore 133 and havingtheir pposite terminal ends disposed in drilled passages 149 and 151provided respectively in mounting disc 134 and head 136 of pin 132.These springs 148 are respectively tensioned during assembly of thelever mechanism by turning the head 136 of pin 132 and its associateddisc 134 in the desired direction until suitable tension is built up inthe spring. The tensioned position of head 136 and disc 134 ismaintained by inserting lock pins 152 and 153 into apertures provided inthe face of bosses 126 and 127 in position to be in the path of thecorners of the hex heads of pin 132 and disc 134. Each of the pins 152and 153 has a force fit in its aperture so as to prevent it fromaccidental dislodgement.

As clearly seen in FIGURES 3 and 4, the lower end of lever 131 extendsdownwardly terminating in a bifurcated terminal end 154 received inaxial slot 118 of spool 29 with the bifurcations in turn receivingbetween them a roll pin 155 carried by spindle 29 and extending acrossslot 118. The upper end of lever 131 is preferably provided with a handgripping ball 156 of hard rubber or the like to provide a suitable gripfor operating the lever 131. While the springs 148 and their tensionedlevers 137 and 138 may be tensioned to maintain the spool 29 in any oneof its three positions, the present embodiment contemplates that thelever 131 be maintained in position to dispose spool 29 in itsintermediate or full shut-01f position shown in solid lines in FIGURE 3and generally designated as the neutral position. This neutral positionis secured by reason of the tensioned arms 137 and 138 respectivelyengaging the opposite ends of pin 144 on opposite sides and forcing thepin 144 and lever 131 into vertically centered relation with respect tostop pins 145 and 146 in a manner that will be clear from an inspectionof FIGURE 3.

Assuming that operation of the valve to supply fluid through ported boss142 is desired, lever 131 will be moved counterclockwise around pin 132to thereby move spool valve 29 to the left as seen in FIGURE 3 to ventboss 43 to the exhaust port 36 and connect boss 42 to the inlet port 35in the manner previously pointed out. So long as lever 131 is held inthis position against the biasing force of lever 139 and its associatedspring 148 fluid flow is assured through boss 42. Upon release of thelever 131, lever 139 and its associated spring 148 will drive lever 131in a clockwise direction until finger 141 of lever 139 engages its stoppin 146. Shifting of the valve to supply fluid through boss 43 isefiected by clockwise movement of lever 131 around pivot 132 to movespool 29 to the right as seen in FIGURE 3 to connect inlet port 35 andthe port in boss 43 as heretofore described and to vent the port in boss42 to the exhaust port 36. Upon release of the lever 131, tensionedlever 138 and its spring will drive lever 131 in a counterclockwisedirection until finger 140 of lever 138 engages its stop pin 145. Inorder to limit the clockwise and counterclockwise movement of the arm131 to assure proper positioning of the valve, lever 131 at points 157'and 158 is notched to respectively engage the upper and lower corners ofbracket arm 68 formed by the intersection of the base wall of slot andthe top and bottom surfaces of bracket arm 68. It will be appreciatedfrom the description just given that the valve of FIG- URES 3 and 4provides a convenient neutral return four way valve in which the valveoperating mechanism is readily accessible and may be convenientlyreplaced and repaired without dismantling any portion of the valveproper.

Referring next to FIGURE .6, there is disclosed a four way one-half inchvalve in which the bracket 68 is modified slightly from that shown inFIGURES 3 and 4. In this form of the invention the bracket arm 68 isformed with a slot 161 of a width sufficient to just freely receivelever 131 and a single boss 126a. The wall of arm 68 at the side of slot161 opposite that containing boss 126a is drilled as indicated bynumeral 162 to a diameter to receive the shank of headed and shoulderedpivot pin 132a and the boss 126a, while provided with a coaxiallyaligned bore 133, is not provided with a return spring. In lieu of ears128 and 129 and stop pins and 146 of the previous embodiment of theinvention, the present embodiment provides an upstanding ear 128a havinga drilled ball receiving opening 165 the outer end of which iscounterbored and threaded to receive a spring abutment screw 166 adaptedto retain a ball detent spring 167 and a detent ball 168 therein forengagement with the side face 169 of lever 131. Lever 131 is notched asindicated at 171 at the lateral midpoint of face 169 to provide a detentnotch for determining the neutral position of the lever and itsassociated spool valve 29. In this form of the invention, the head 136of pin 132a is assembled with the lever 131 and spool valve 29 inneutral position and the disc securing pin 152 is driven home so as tolie against a face of head 136 to restrain pin 132a against rotationalmovement when lever 131 is moved. In this form of the invention, manualforce sufficient to overcome the holding effect of the detent ball moveslever 131 in either a clockwise or counterclockwise direction as desiredto move the valve to either of its operative positions or its neutralposition.

Referring now to FIGURE 7, a four way three-eighths inch valve is shownequipped with a bracket member 68 similar to that just described inconnection with FIG- URE 6. The operating lever 131a in this embodimentis provided with a foot treadle 173 in lieu of the hand controllingknob. The lower arm of lever 131a. of this form of the invention isidentical to that heretofore described in connection with FIGURE 6 andthe foot treadle 173 is integrally formed on the upper arm as will beclear from the drawing. However, the ball detent 1'71 and its spring isomitted and a return spring 148 is provided and tensioned, as willappear from the different location of the spring pole 164 in FIGURE 7,in a direction to bias the lever 131a and treadle 173 to the outermostposition of spool 29 for supplying pressure fluid to the port in boss 42and venting the port in boss 43 to the exhaust port 36 through themanifold chamber 37 as previously pointed out. The position of spool 29in FIGURE 7 corresponds to that shown in FIGURE 5 so that upon rockingmovement of the treadle 173 in a clockwise direction around pivot pin132a the spool 29 will be successively moved to the intermediate neutralposition and then to the other extreme position in which the port inboss 42 is vented through the exhaust port 36 and the port in boss 43 isconnected to the fluid inlet 35. Release of the foot treadle in thisform of the invention results in counterclockwise movement of the lever131 around pivot pin 132a to return the spool valve 29 to the positionshown in FIGURES 5 and 7. It will thus be clear that the levermechanisms of this invention, by simple selection and adjustment of thetension of springs 148 and appropriate use or non-use of 1 1 balldetents can either be set to bias the valve to any one of the threenormal operating positions or to serve as a full manual valve.

Referring next to the operating mechanism disclosed in FIGURES 8 and 9of the drawings, there is illustrated a one-half inch four way valveprovided with a bracket member 67 in all respects identical to that justreferred to in connection with FIGURE 7, including the tensioning ofspring 148 to normally bias the spool 29 to its extreme right handposition. In this form of operating mechanism, the lower arm of theshaft 1311) again is provided with bifurcated end portion 154 but theupper end is provided with a right angularly extending arm 175 which isitself bifurcated at its outer end to provide laterally spaced arms 176and 177. These arms are suitably apertured to receive the opposite endsof a roll pin 178 provided to journal a cam roller element 179 thereon.This particular operating mechanism through the cam roller element 179is adapted for machine operation rather than foot operation aspreviously pointed out in connection with FIGURE 7.

Referring next to FIGURE 10, a four way one-half inch valve equippedwith a bracket member 67 identical to that described in connection withFIGURE 7 is again illustrated. In this form of the invention, the spring41 is tensioned as previously described in connection with FIGURES 8 and9 and the operating lever 1310 with a lower bifurcated end 154 asheretofore described is provided with a right angularly disposed arm 181terminating at its outer end in a toe pad 182 for effecting itsoperation. In all other respects, the operating mechanism of thisembodiment is identical to that heretofore described in connection withFIGURES 8 and 9.

Turning now to FIGURES 11 and 12, there is disclosed a one-half inchthree way valve made from a body 27b in the manner heretofore described.In this form of the invention, it will be noted that a singleintermediate liner member 45 is used with end liners 46 and 47, that aspool 29a embodies the single reduced diameter portion extending fromthe inner ring groove adjacent valving land 93 to the inner ring grooveadjacent the second valving land 185 at the inner end of the spool. Thisland 185 at the side nearest the inner end of spool 29a is provided withan end seal ring 96 similar to that heretofore described and a similarring 96 is provided at the r outer end of land 93. The remaining spoolrings 94 are of the high pressure type heretofore referred to. Theliners 45, 46 and 47 and the spool valve 29:! of this form of theinvention function substantially like those of the four way valvesheretofore described. However, the end cover plate assembly 71a of thisform of the invention is provided with a breather opening 186 containinga suitable packing 187 for venting the inner end of the spool 29a sincethere is no manifold passage and vent passage in these three way valves.This breather opening and packing, it will be appreciated, is drilled inthe standard cover plate 71 at the time the cover plates are applied touse on the three way valve structures. It, accordingly, will be seenthat the same cover plate suflices for all valves.

As clearly appears from FIGURE 11 the three way valves are admirablysuited for operation with the identical operating mechanisms heretoforedescribed in connection with the four way valves since these three wayvalves have three spool operating positions also. The extreme right handposition shown in FIGURES l1 and 12 supplies fluid from inlet opening 35to right hand outlet port 41 while outlet 39 is completely shut-01fthrough land 185 and its associated rings 94 and 96. In this position,the high pressure fluid supplied by inlet 35 enters between seal rings94.

The neutral position of this valve spool 29a is that in which the twospaced sealing rings 94 engage the opposite end portions of the linerelement 45. In thi position lands 93 and 185 together with theirassociated rings 12 94 and 96 respectively close off both outlet ports39 and 41 while the high pressure fluid entering from inlet port 35 isagain confined between the two spaced seal rings 94.

The third position of the spool valve 29a of the three way valves ofthis invention is the extreme left hand position. In this position theland and its associated sealing rings 94 and 96 are disposed whollywithin the valve liner 46 and the valve land 93 is disposed with itssealing ring 94 in the right end of liner 45 and its support ring 96 inthe inner end of liner 47. In this position, high pressure fluid frominlet 35 is again confined to the annular space defined by the reducedsection of spool 29a between rings 94. The operator, as disclosed inFIGURE 11, has its spring 148 wound so as to bias the spool valve 29a toits extreme right hand position, namely, the position shown in FIGURE12. It, however, will be clear from the preceding description that powerbiasing of this valve could be effected to normally bias the spool valveto either one of the other positions if desired.

Referring to FIGURE 13 a two-way valve made in accordance with thisinvention is illustrated in section. Except for the shortening of thevalve body 27c to eliminate the outlet port 39 this valve issubstantially identical to the three way valve just discussed. In thisconnection it will be noted that a valve spool 29]) having a singlevalving land 93 between sealing ring 94 and support ring 96 is providedfor the two-way valves. This spool valve 2% has a reduced portionextending away from sealing ring 94 to the terminal end ring structure188 containing an end support and seal ring 96 similar to thatheretofore described. It will also be noted that these two way valvesemploy a single intermediate liner member 45 on end of which abuts thecover plate 71a and the other end of which cooperates with the adjacentend of an end liner element 47 similar to that shown in FIGURE 12. Thisvalve in operation has two positions. The first position, shown inFIGURE 13, connects the inlet 35 with the outlet port 38 with the innersealing rings 94 and 96 effectively engaging the liners 47 and 45respectively to seal off the fluid from the ends of liner bore 48. Inthe other position, namely, the left hand position, the ring 94 willsealingly engage the right hand end of the liner element 45 and ittogether with the outer sealing ring 96 will seal off the inlet 35. Atthe same time land 93 will overlie the annular passage formed betweenthe ends of liners 45 and 47 with the ring 94 and outer ring 96 sealingthe outlet 38 against retrograde flow of fluid therethrough. Any one ofthe valve operating mechanisms heretofore described in connection withthe three and four way valves may be provided on the operating bracket67 as will be apparent to those skilled in the art.

In all forms of the valves drilled openings 199 extending at rightangles to the support faces of feet 31 and clear through the valve bodyare provided for the mounting screws.

While a one piece spindle of the type heretofore illustrated may beeffectively employed in any of the valves of this invention, greaterassurance against a blowout of seal rings 94 in high pressure usagewhere the pressure differential is unduly high on the ring between theinlet and exhaust porting is provided by the novel multi-part spool 290of FIGURE 13a. As disclosed in FIGURE 13a, spool 29c is made up of anend section 201, an intermediate section 202 and a second end section203. End section 201 provides land 93, the ring groove for outer sealring 96 and the protruding end slotted at 118. The end of land 93adjacent high pressure seal ring 94 is recessed to provide an annular,axially curved ring retainer lip 204. This same end of land 93 is alsoprovided with a coaxially disposed reduced portion or anchor pin 205 ofa diameter to provide the annular base of the ring groove and a stillsmaller reduced terminal mounting stem 206.

Intermediate section 203 is symmetrically formed at opposite sides ofland 92 to provide oppositely directed reduced sections terminating attheir free ends in respective annularly enlarged flange formations 207.The exposed faces of flanges 207 are recessed similarly to the end ofland 93 just described to form annular, axially curved ring retainerlips 204 facing in opposite directions. The opposite ends of section 203in coaxial relation to flange lips 204 are provided with axial bores 208slightly exceeding in length the axial dimension of stem 206 and havinga diameter adapted to snugly receive stem 206 so as to form a lightpress fit.

The section 203 contains land 91 and its related ring groove forreceiving O-ring 96 adjacent its free end. The opposite end of land 91is recessed in a manner identical to the inner end of land 93 to providean annular, axially curved ring retainer lip and is provided with areduced portion 205 and a mounting stem 206 identical to that formed onsection 201.

In assembling the multi-part spool 290, the 80 Durometer hardness rings95 are first assembled on opposite sides of land 92 in the usual way.Then the 90 Durometer hardness rings 94 are positioned on reducedportions 205 of sections 201 and 203 and the stems 206 of these sectionsare then aligned with the bores 208 of section 202 and pressed hometherein until the radial shoulders of reduced portions 205 abut theopposed end faces of the recessed end of section 202. The result is thatrings 94- are gripped between the opposed recessed ends of sections 201and 202 on the one hand and 202 and 203 on the other hand with theirouter peripheral surfaces being partially overlapped by the respectiveopposed retainer lips 204. The remaining rings 96 are then assembled inthe conventional manner by forcing them over the peripheral surfaces ofthe free ends of sections 201 and 203.

Assuming the spool 290 to be in place in a four way valve body asheretofore pointed out and that an excessive pressure tending to forceone or the other rings 94 into the exhaust passage as it passes over theannular opening between liner 45 and either liner 46 or 47, the highpressure fluid will have forced the particular ring tightly against therecessed end of its respective land 91 or 93 and entered under the ring94. This high pressure fluid will then have to act radially to force thering radially through the restricted opening between opposed lips 204.Such radial movement of the ring 94 along the axially curved surface ofits respective land will bodily shift the ring axially toward theopposed recessed face of section 203 causing it to assume a positionspanning the restricted opening. At the same time that full sealing ofthe restricted opening occurs the volume of the space radially inwardlyof ring 94 will have increased and the effective blowout pressure willhave been reduced below its blowout value. The ring 94 by this time willhave passed over the annular exhaust passage to vent the high pressureto exhaust and become confined by the encircling liner wall. Theconditions essential for blowing of ring 94 will, therefore, havesubsided with the result that blowing is eflectively prevented as apractical matter.

Since end section 201 in all forms of the valves heretofore describedare identical, it will be appreciated that the valve spools 29a and 29bmay also be provided with this blowout prevention feature by similarconstruction of the related intermediate and inner end sections of thethree way valve spool and formation of the outer end of the end sectionof the two way valve in the manner just described with respect tosection 202 of the four way valve spool.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

l. A multi-part valve spool comprising an end section having one endadapted for connection to an operator for axially reciprocating saidspool, an annular ring groove formation spaced axially inwardly fromsaid one end and formed by an axially extending ring receiving reducedportion and an integrally formed radial shoulder the end face of whichat its outer marginal portion is curved axially to form an annular lipoverhanging said reduced portion and an axially extending mounting stemof further reduced diameter extending from the free face of said ringreceiving reduced portion; a mating section having a peripherallydisposed valving land formed thereon between its opposite ends andflanked on at least one side by a ring groove and at least one endproviding a radial face the outer marginal portion of which is curvedaxially to form an annular overhanging lip and the center of which isprovided with an axial bore dimensioned to snugly receive said mountingstem in a press fit, said end section and said mating section being connected in assembled relation with said stem in said bore and said ringreceiving reduced portion in end abutment with said one radial face ofsaid mating section to dispose said opposed overhanging lips in axiallyspaced relation defining an annular ring groove; an O-ring disposed insaid ring groove in peripherally spaced relation to said respectiveopposed faces of said sections and with an axially centered peripheralportion disposed in the space lying between said lips to provide a boresealing portion, said O-ring, when distended by the line pressure whilepassing over an annular port of a valve bore, being adapted to sealinglyengage the curved portions of said opposed lips; and an O-ring sealdisposed in said ring groove flanking said valving land.

2. The spool structure in claim 1 wherein said valving land on saidmating section is longitudinally centered between the ends of saidmating section and is flanked on opposite ends by ring grooves, theother end face of said mating section has its outer marginal portion.curved axially to form a second oppositely extending, annularoverhanging lip and a centered axial bore; and a further end sectionhaving a terminal land formation at one end, an axially extending ringreceiving reduced portion, an end face at the inner end of said lastmentioned reduced portion and having its outer marginal portion curvedaxially to form an annular overhanging lip and an axially extendingmounting stem of further reduced diameter centered on said opposite endface and dimensioned to snugly fit said bore in the other end face ofsaid mating section, said further end section and said mating sectionbeing connected in assembled relation with its stem in said bore of saidother end face and said last mentioned ring receiving reduced portion inend abutment with said other end face of said mating section to disposesaid last mentioned opposed overhanging lips in axially spaced relationdefining an annular ring groove; an O-ring disposed in said lastmentioned ring groove with an axially centered peripheral portionextending outwardly between said lips to provide a bore sealing portion;and an O-ring seal disposed in end flanking relation to the inner end ofsaid terminal land formation.

3. A valve spool for use in a valve body having an elongated valve boreintersected at a plurality of axially spaced points by an inlet passage,21 pair of axially spaced outlet passages, and a pair of annularlycontinuous axially spaced exhaust passages comprising an elongatedslidable member having longitudinally spaced annular lands; respectiveO-rings in each of said lands forming slidable and sealing supportsbetween said lands and said bore, each slidable member land beingseparated by stem portions of reduced diameter forming through the spacesurrounding the respective adjacent reduced stem portions of the valvemember axially extending connection passages for connecting a respectiveone of said outlet passages and said inlet passage and a respective oneof said outlet passages and its exhaust passage; means for shifting saidslidable member to establish communication, through said respectiveaxially extending passages, between the other of said outlet passagesand said inlet passage and said respective one of said outlet passagesand its exhaust passage, said O-rings disposed to pass across saidannularly continuous exhaust passages being formed to have an outerdiameter -8% greater than that of said valve bore and an outer diameterrelated to the cross-sectional diameter in the ratio of 4 to 1 withcustomary manufacturing tolerances.

4. A slidable valve member for use in the valve bore of a valve havingannularly continuous porting to be passed by ring seals comprising anelongated cylindrical member having enlarged end portions radiallydimensioned to annularly clear said valve bore and grooved uniformly inaxial length and depth to receive annular O-rings and form actuatingpiston portions at each end; a plurality of reduced stem portionsextending between said piston portions, formed at their respectiveadjacent ends with enlarged cylindrical formations radially dimensionedthe same as said end formations to annularly clear said valve bore andeach containing at least one annular groove of predetermined equal widthand depth, said stem portions between said enlarged cylindricalformations at their respective opposed ends, cooperating with said valvebore to provide elongated annular spaces adapted in use to formelongated passages for fluid under pressure; and an O-ring of normallycircular cross-section in each of said grooves having a cross-sectionaldiameter approximately Smaller than the Width and depth of the groove,an outer diameter 5-8% greater than the diameter of said valve bore andan outer diameter to crosssectional diameter ratio of 4 to 1 wherebysaid O-rings when assembled will extend beyond the peripheral walls ofsaid enlarged end portions and said enlarged cylindrical formationssufiiciently to assure that the O-rings constitute the sole contact withsaid valve bore and thereby slidingly and sealingly support said valvemember in said valve bore.

5. A slidable valve member for use in the valve bore of a spool valvehaving annularly continuous porting to be passed by ring sealscomprising an elongated cylindrical member having enlarged end portionsradially dimensioned to annularly clear encircling end portions of saidvalve bore and annularly grooved to receive O-ring seals, a plurality ofreduced stem portions extending between said enlarged cylindricalformations, radially dimensioned to annularly clear encirclingintermediate portions of said valve bore and respectively separated byan enlarged annular land having at each end at least one annular grooveto receive an annular seal ring, said stem portions providing betweensaid enlarged end portions elongated annular spaces adapted in use toform axially extending flow passages for fluid under pressure, andO-rings of resilient material in each of said grooves having an outerdiameter 58% greater than the diameter of said valve bore and across-sectional diameter related to the outer ring diameter in the ratioof 1 to 4 with customary manufacturing tolerances.

6. A valve spool for use in a slidable spool valve having a body formedwith an axial bore and generally radially directed inlet, outlet andannularly continuous exhaust ports intersecting said axial bore ataxially spaced points comprising an axially slidable member providingsmall diameter stem portions and axially spaced, annularly groovedlarger diametered valving lands defining the opposite ends of annularport connecting passages encircling said stem portions of said spoolmember; and O-rings of resilient material disposed in said respectiveannular land grooves, the said O-rings cooperating with the outlet portsand passing across the annularly continuous exhaust ports and beingconstructed of a material having a Durometer hardness of at least andhaving an outer ring diameter 5 to 8% greater than the diameter of saidaxial bore and a cross-sectional diameter related to the outer ringdiameter in the ratio of 1 to 4 with customary manufacturing tolerances.

7. The spool member of claim 6 wherein the spool member is fabricatedfrom a pair of end sections each having a shallow cupped inner end walland a reduced diameter anchor pin portion protruding from said inner endwall and an intermediate section having oppositely facing shallow cuppedend Walls each of which surrounds an axial bore dimensioned to form atight press fit with the reduced diameter anchor pin portion of arespective end section, the respective cupped end walls of said endsections cooperating in the assembled relation of said spool membersections with a respective cupped end wall of said intermediate sectionto impart to said innermost grooves of the outlet port lands undercutring gripping groove walls.

8. The spool member of claim 6 further characterized by said spoolmember outlet port lands at the ends adjacent the respective spool endsbeing provided with resilient spool supporting O-rings of substantiallylower Durometer hardness having a squeeze fit with said axial bore and across-sectional diameter to fill their respective grooves and form afirm support for said spindle.

9. The spool member of claim 8 wherein one end of said spool memberprotrudes beyond its body end face, is bifurcated to provide anoperating lever slot and provided with a transverse pin receivingopening and a cross pin adapted to pnovide an operating leverconnection.

10. The spool member of claim 6 wherein said spool member has at leastone annularly grooved inlet port valving land disposed between saidoutlet port valving lands and resilient O-ring means of substantiallyless than 90 Durometer hardness mounted therein to effectively seal saidaxial bore between said inlet port and one or the other of said outletport lands in operation of said valve.

References Cited in the file of this patent UNITED STATES PATENTS2,417,494 Hoof Mar. 18, 1947 2,600,746 Ernst June 17, 1952 2,605,079Miller et al July 29, 1952 2,621,676 Loft Dec. 16, 1952 2,621,885Schmitt Dec. 16, 1952 2,690,360 Young Sept. 28, 1954 2,704,650 Rand Mar.22, 1955 2,808,811 McLaughlin Oct. 8, 1957 FOREIGN PATENTS 472,593France Dec. 10, 1914 702,088 Great Britain Jan. 6, 1954 OTHER REFERENCESHandbook of 0 Ring and Dynaseal Packings Precision Rubber ProductsCorporation, p. 15, copyright 1953.

